Can You Mix 5w20 And 5w30 [You Must Know]

Can you mix 5W20 and 5W30? This is a common question we found on different forums. Most car owners say they mix the oil unwillingly or force it to mix as they didn’t have sufficient oil at that moment. 

The viscosity of both 5W20 and 5W30 is the same. So, you can mix them and pour them to run your engine smoothly. To learn more about mixing 5w20 and 5w30, keep scrolling. 

Can You Mix 5w20 And 5w30

Yes, you can mix 5W20 and 5W30 and it doesn’t bring any harm to your engine. Both the oils have the same viscosity (5W) though the viscosity index is different. 

Of course, the two oils have different additives as there is a difference between viscosity index ratings. But, it doesn’t pose any harm to your engine. 

Now, the question is- why do you want to blend these two oils? If it’s because your oil is low and blending oil is the only option, it might be fine until you get it changed. 

We recommend you stay with the weight and grade of oil you are running in the engine. If possible, go to your local store and get a few quarts of oil your car manufacturer recommends. 

Note: You can also read Can I Mix 10w30 With 5w30.

What Happens If You Mix 5W20 With 5W30?

Nothing significant will happen if you mix 5W20 with 5W30. Indeed, your engine will be fine. However, it may void your warranty if you tell the dealer about it. 

Today’s multiple viscosity oils work with a wide range of ambient temperatures. If you don’t drive your car in 120F heat or -30F cold, you can pour either 5W20 or 5W30 without fear of damaging your engine.  

Indeed, 5W20 and 5W30 oils are interchangeable and your vehicle engine will run smoothly if you blend these oils and pour them. 

Keep in mind; both the 5W20 and 5W30 should come from the same manufacturer and the same API classification if you want to mix them. 

Is Mixing 5w30 With 5w20 Bad

No, mixing 5W30 with 5W20 will not pose any negative effects on your car engine.  

However, you should consider some points. 5W20 oil is comparatively lighter and designed to work with newer engines. It will improve fuel efficiency because of less drag resistance along cylinder walls, bearings, and other moving parts that are in contact with each other. 

5W20 is thinner than 5W30 though the safe operating temp range is almost the same. The 5W20 engine oil is favorable in cold climates and also well below 32°F ambient temperatures. 

On the other hand, 5W30 oil is preferable in extremely high ambient temperatures, over 120F. If you pour 5W20 oil into an old car, your engine will run a little bit dry. But pouring the mixture of 5W20 and 5W30 will not bring any damage to your engine. 

5w20 Vs 5w30 In Hot Weather

In hot weather, 5W30 works more efficiently than 5W20. It doesn’t break down quickly due to exposure to heat. Due to its thickness, it provides better engine protection in hotter conditions than the 5W20. 

On the other hand, 5W20 is less viscous compared to 5W30. So, it thins out quickly and exposes the engine parts to wear & friction. So, we recommend you go for the 5W30 if you drive your car in hot weather

5w30 Or 5w20 For High Mileage

Both 5W30 and 5W20 are perfect for high mileage cars. But which viscosity rate will be best for your car depends on how the manufacturer designs the engine. If the manufacturer advises you to pour 5W20 into its engine, stick with it. On the other hand, using 5W30 will be your best bait if the manufacturer recommends it. 


What Is The Difference between 5w30 and 5w20?

Though the viscosity (5W) of these two oils is the same, the weight of the two oils is different. As the viscosity rate of 5W30 is higher than the 5W20, it is perfect for hot weather due to its thickness. It doesn’t break down easily in warmer temperatures. On the other hand, 5W20 thins out quickly, which is perfect for cold climates as it reaches every part of the engine. Indeed, 5W30 is thick, while 5W20 is thin. 

Can you mix 5w20 and 5w40?

Yes, you can mix these oils without the fear of hurting your engine.  

Can you mix 5w20 and 10w30?

It will be fine for your engine. But don’t overfill the engine with the mixture. We recommend you change the oil as soon as you can. 


We hope you get the answer to this question: Can you mix 5W20 and 5W30? Yes, you can. It will be best if both these oils come from the same brand with the same API classifications. The best suggestion for you is to stick with the same oil your manufacturer recommends. 

About John M

John contributed as a technical head at an automobile company just 2 years after his post-graduation in Automobile Engineering. He loves to lead a free life, so he left his job & started blogging. Now, he does research on every automotive problem, part & product and seeks a better solution & best products & shares his findings with his readers to help them as well as to minimize their struggle.

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